Gestation loss was more common in primiparous and multiparous than in heifers and first AI was related to higher loss rates than second or subsequent AI.
The use of equine chorionic gonadotropin in dairy cows during the postpartum improves the uterine health by reducing vaginal discharge.
In the relatively recent past different devices were developed to monitor estrus. Examples are those that record increased cow activity alone (pedometers), or a combination of the latter with a reduction in intake and rumen motility.
Extended lactation, the management practice in which the time of first insemination is delayed deliberately, increases calving interval and reduces the proportion of dry cows in the herd.
Traditionally, the methods used to detect estrus in dairy cows include visual observation, tail painting, tail chalking, rump-based pressure and scratch-off patches.
It has been shown that using sex-sorted semen reduces fertility which can be caused by the sorting process of the sperm altering the fertilizing capacity and viability of spermatozoa.
